Hi all,
I found that AWB will fail to control when the module is placed in dark environmont, which can be seen in the fingure below, the image looks very greenish. As the light brightens, the image returns to normal. The problem did not disappear after re-calibration AWB.
There are the AWB calibration result and xml file. please help me check.
Thanks.
Hi Zhili,
I see several suspicious things in your shared images and tuning projects, but your output YUV images does not match well with the xml files.
So, I am not sure what is actually used in your system and which one is actually causing you trouble.
1. AWB tuning is roughly correct, but it looks like having black level issues.
Your AWB plugin has black level of 0 (rather than 64) for each input raw file, but changing them to 64 does not really help.
That suggests there might be some problem in the raw images (could be due to lens flare/glare or nonlinear sensor response).
2. Your "normal-bright environment.yuv" has WB issue on the white patch and the wall of the lightbox.
That also suggests nonlinear response in sensor.
3. Your "OVX3C-MAX9295_MARS_h3a_aewb_dcc.xml" in X3C project is not valid, but the GUI input values are OK.
I am not sure what is actually used in your actual system because the invalid values would cause driver error.
Please redo H3A plugin in tuning tool V3.0 and export to the xml file.
4. Your H3A parameter has H3A input is b5~b14 out of 20b, which is b9~b18 out of 24b.
That will make your H3A input very dark for "normal-bright" and almost 0 for "dark" scene.
Then, AWB will not have good scene information in input to work properly.
The last one (4) may be the main cause of your trouble in dark conditions.
Please try lower values (note that it will affect AE as well).
How to set black level in AWB plugin? I didn't see the way.
This may because of the calibrition of AWB is not so good.
It does not look like.
The other gray patches are much better and consistent.
BTW, do you have any advice on how to tuning H3A plugin?
You may try similar settings as IMX390 in PSDK as a start point (e.g., 32H x 16V windows).
H3A input bit may start at b0, b1, or b2 out of 20b on GUI (higher values may give more issue in low light).
For 24-bit WDR, most customers use gamma value around 0.5.
Hi Gang,
There is a good news that the greenish image become normal in low light after reset the H3A parameter, thank you very much.
I put the new H3A xml file export from DCC V3.0 here, the previous one is also attached.
Howerer, I have some questions about this problem:
1. Is the greenish image in low light caused by the wrong statistic data judging by the results so far?
2. If I set the value of "output 10 out of 20 linear bits from LSB#" to 5, does that mean the data below b5 will not be used for AE/AWB process?
3. I found that the value of "v_skip" and "h_skip" in "_h3a_aewb_dcc.xml" exported from DCC V2.5 is 2 while the one exported from DCC V3.0 is 4, the parameter settings of the two software are the same, which is shown in below:
Is the results from V3.0 recommended?
Thanks.
BR.
